<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>回调函数</title>
</head>
<body>
    <p>回调函数：</p>
    <script>
        function a(x,y){
            return x+y;
        }
        function b(x,y){
            return x-y;
        }
        function c(x,y){
            return x*y;
        }
        function d(x,y){
            return x/y;
        }
        function fn(x,y,m){
            return m(x,y);
        }
        alert(fn(5,2,c))
    </script>
</body>
</html>